A few years ago (2009-2010) I made a sailing simulation demo. This video shows some footage from this demo:
The sailboat model is motivated by the real physics of sailing, but it is not 100% correct. I made a dynamical system that roughly approximates the real thing. After reading several white papers, I realized that making a “real” simulator would be a huge endeavor and so I cut few corners :-). But even with my simplifications, the model can tack realistically, can get stuck “in irons”, the wind can blow the boat backwards, etc. Also, I implemented a simple collision system, AI that drives NPC boats (with red sails), line of sight, wave/ocean simulation, skeletal animation, light, crafted 3D models, etc. AI that controls NPC boats does not cheat and controls the same dynamical system as the player’s boat by doing global optimization over the control/goal function. The goal of the NPC boats is to catch the player’s boat with white sails. The demo uses DirectX 9.0 and uses a basic framework that comes with DX9 code samples.
You can use the demo source code if you wish (as is and with no warranty). The ZIP file with the C++ source code (VS 2010 project), shaders and the demo executable (runs on Windows with DX9 installed) is located in this file – SailingSim.zip